The various embodiments of the present invention relate to a photochemical method of making decorative designs, including tactile designs. The tactile design of the present invention is capable of being perceived by the human touch.
The Federal Americans With Disabilities Act (ADA) mandates, inter alia, that public signs incorporate a raised or tactile design capable of being perceived by the touch of visually impaired people.
Conventional processes for making tactile designs typically require a great deal of time and expensive equipment, are limited in color spectrum, can not place one color touching another, are limited in ability to reproduce fine detail, can not easily do multiple colors on one sign (if at all), and are extremely limited in creative latitude. Existing processes are so complex and sensitive to failure that they are impractical and prohibitive for use by the small sign shop. Some examples of conventional processes which can be used to produce signs having a raised or tactile design are engraving (routing), hot stamping, and embossing.
Hot stamping requires expensive and bulky equipment capable of exerting several tons of pressure on the substrate to generate the desired design. Generally, this process is only suitable for operations which can exploit high production rates. Furthermore, there is a high failure rate in producing commercially acceptable product. It is difficult and extremely costly to do more than one color with hot stamping methods. The color spectrum is limited and one color can never touch another color.
Embossing requires expensive male and female dyes which are combined and then applied to the substrate under several tons of pressure. Similarly, expensive and bulky machinery is required so that, in general, this process is restricted to high volume operations. The embossing method also carries a high failure rate in producing commercially acceptable product. Further, adding secondary colors is difficult and expensive and any added colors are limited and can never touch one another.
Engraving or routing requires the removal of substrate material outside of the desired image area. The equipment is relatively expensive and the process offers limited color treatment to the image area. Engraving or routing an average sign requires an inordinate amount of machine time (wear and tear). The process also produces sharp-edged raised designs which are uncomfortable to the reader and, therefore, are undesirable.
Another conventional process is silk screening; it may be used to top-coat a tactile design feature. This process requires expensive screens and copious amounts of ink. Excess ink is needed to be certain that it penetrates the screen mesh. There is a large failure rate in achieving a commercially acceptable product. Adding second, third, etc. colors is difficult and expensive. One color can not touch another color. Additionally, the silk screen process involves extensive equipment clean-up using large quantities of chemicals which may require containment and disposal.
Another conventional process for creating a raised design is the chemical etching of metal plates such as copper, brass, zinc, and magnesium. This process requires the use of costly equipment and large quantities of extremely hazardous chemicals. The chemicals used typically mandate containment and disposal procedures.
It is apparent that presently available processes for the application of a tactile design to a substrate surface requires expensive and bulky machinery, are limited in creative concepts and applications, and produce excessive quantities of unusable/unsalable product. The equipment for these conventional processes must be connected to sources of heat and pressure. Accordingly, the process machinery and ancillary equipment require a large physical plant and capital investment which thereby dictate a high output to achieve an adequate economic return. Generally, small custom design jobs are rendered uneconomical.
For the foregoing reasons, there is a need for an inexpensive and less time-consuming process for producing tactile designs on substrate surfaces. In particular, an economical method is needed for satisfying custom design jobs.